1. Field of the Invention
The present invention relates to a receipt-issuing printer for use in, for example, a POS (Point-Of-Sale) system. In particular, the present invention relates to a printer which can be selectively arranged horizontally or vertically and which, in either of the horizontal or vertical arrangement thereof, is capable of detecting the residual quantity of rolled-paper.
2. Description of the Related Art
Conventionally, as a printer of the above type, there is known a printer which executes given printing on a roll of recording paper and, after printing, cuts the printed recording paper in order to issue the same as a receipt. Also, as a printer of this type, there is known a printer which can be selectively installed or arranged horizontally or vertically.
The printer of this type, as shown in FIG. 6, includes a box-shaped rolled-paper holder 101 capable of storing rolled-paper R therein. The printer is structured so that by opening and closing a holder cover 103, disposed in one end portion 102 of the rolled-paper holder 101, the rolled-paper R can be inserted into or taken out from the rolled-paper holder 101.
The rolled-paper holder 101 includes a residual-paper-quantity sensor (not shown) which is used to detect the residual quantity of rolled-paper R. The residual-paper-quantity sensor is structured so that when a sensor elementxe2x80x94formed so as to be pressed against the end face of the rolled-paper Rxe2x80x94 is inserted into the hollow core portion 104 of the rolled-paper R due to the reduced diameter of the rolled-paper R, a limit switch is operated thereby signaling that the residual quantity of the rolled-paper R is small.
Also, the above-mentioned rolled-paper holder 10 includes, in every installation direction, a plurality of grooves which can be used by the residual-paper-quantity sensor for detection of the residual quantity of the rolled-paper R. When the printer is installed horizontally with the bottom portion 105 of the rolled-paper holder 101 facing downward, the rolled-paper R having a little residual quantity drops into horizontal-installation groove 106 formed in the bottom portion 105 of the rolled-paper holder 101. In this state, the residual-paper-quantity sensor is able to detect the residual quantity of rolled-paper R.
On the other hand, when the printer is installed vertically with the end portion 102 of the rolled-paper holder 101 facing downward, the rolled-paper R having little residual quantity drops into vertical-installation groove 107 formed in the end portion 102 of the rolled-paper holder 101. In this state, the residual-paper-quantity sensor is able to detect the residual quantity of rolled-paper R.
3. Problems to be Solved by the Invention
Generally, since this type of printer is designed to use rolled-paper R having several kinds of diameters, it must be sized based on the rolled-paper having the largest diameter. That is, in order to store rolled-paper in the rolled-paper holder, the opening of the rolled-paper holder must be sized so that when it is opened it corresponds to the size of the rolled-paper having the largest diameter. Further, the portion of the rolled-paper holder for storing the rolled-paper must be formed so as to correspond in size to the rolled-paper having the largest diameter.
In the above-mentioned conventional printer as shown in FIG. 6, however, it is difficult to obtain miniaturization. Even when attempting to minimize the storing space of the rolled-paper holder 101, the vertical-installation groove 107 is still formed in the vicinity of the support shaft of the holder cover 103. Therefore, the storing space of the rolled-paper holder 101 must be enlarged by an amount equivalent to the vertical-installation groove 107. Accordingly, there is a limit to miniaturization of the rolled-paper holder 101 and thus to the printer itself.
The present invention aims at solving the above technical problems found in the conventional printer. Accordingly, it is an object of the invention to miniaturize a printer which is capable of detecting the residual quantity of rolled-paper in either of its horizontally or vertically installed states.
In order to attain the above and other objects and advantages, according to a first aspect of the invention, there is provided a rolled-paper holding mechanism, including: a rolled-paper holder capable of storing therein rolled-paper having a given diameter;
a holder cover disposed on said rolled-paper holder such that said holder cover can be opened and closed by moving about a first pivot;
a groove-like guiding portion formed in said rolled-paper holder, said rolled-paper being located on said groove-like guiding portion when said rolled-paper has a small diameter which is smaller than said given diameter; a paper sensor for detecting a remaining amount of said rolled-paper, said paper sensor provided by the side of said groove-like guiding portion; a retractable positioning member pivotally supported on a second pivot provided in the vicinity of said first pivot, said positioning member being movable together with said holder cover, and forming part of said groove-like guiding portion when said holder cover is closed.
According to the first aspect of the invention, for example, a positionxe2x80x94which is present within the vertically arranged rolled-paper holder and at which the residual-paper-quantity sensor is able to detect the rolled-paperxe2x80x94is set as the second position, the rolled-paper is inserted into the rolled-paper holder, and the holder cover is closed. As the diameter of the rolled-paper decreases during use, the rolled-paper is held in the second positioning groove which is formed between a given portion of the rolled-paper holder and the positioning member. Due to this arrangement, there is no need to form a vertically arranged groove in the rolled-paper holder. Also, since the positioning member is rotated about the peripheral portion of the support shaft of the holder cover, the positioning member can be prevented from blocking the storing space of the rolled-paper holder.
Therefore, according to the first aspect of the invention, a storing space that is matched in size to the rolled-paper having the largest diameter can be formed within the rolled-paper holder. This makes it possible to reduce the size of a rolled-paper holding mechanism which is capable of detecting the residual quantity of the rolled-paper in both horizontally arranged and vertically arranged states.
Also, according to a second aspect of the invention, in rolled-paper holding mechanism as set forth in the first aspect of the present invention, said second pivot is provided at an end of said retractable positioning member, and said rolled-paper holding mechanism further includes:
an engagement shaft formed at an opposite end to said end of said retractable positioning member,
an engagement hole provided with said holder cover, said engagement shaft being engaged in said engagement hole.
Further, according to a third aspect of the invention,
A rolled-paper holding mechanism as set forth in first aspect of the invention, said rolled-paper having said small diameter is located on said groove-like guiding portion when said rolled-paper holding mechanism is mounted in a vertical attitude,
said rolled-paper holding mechanism further includes a second groove-like guiding portion formed in the rolled-paper holder, wherein said rolled-paper having said small diameter is located on said second groove-like guiding portion when said rolled-paper holding mechanism is mounted in a horizontal attitude.
Still further, according to a fourth aspect of the invention, in a rolled-paper holding mechanism as set forth in the second aspect of the present invention, said rolled-paper having said small diameter is located on said groove-like guiding portion when said rolled-paper holding mechanism is mounted in a vertical attitude,
said rolled-paper holding mechanism further includes a second groove-like guiding portion formed in the rolled-paper holder, wherein said rolled-paper having said small diameter is located on said second groove-like guiding portion when said rolled-paper holding mechanism is mounted in a horizontal attitude.
Still further, according to a fifth aspect of the invention, a rolled-paper holding mechanism as set forth in the second aspect of the present invention, further includes:
a rolled-paper holding mechanism as set forth in claim 1, and
a printing mechanism adapted to print on recording paper pulled out from said rolled-paper held in said rolled-paper holder. Still further, according to a sixth aspect of the invention, a rolled-paper holding mechanism as set forth in the fifth aspect of the present invention further includes:
a cutting mechanism that is adapted to cut said recording paper after said recording paper has passed through said printing mechanism.
According to the present invention, the above-mentioned rolled-paper holding mechanism, printing device, and cutter device are combined together. Because of this combined arrangement, a printerxe2x80x94which is capable of detecting the state of the residual quantity of the rolled-paper whether the printer is installed horizontally or verticallyxe2x80x94can be reduced in size and, especially, a printer used to issue a receipt can be miniaturized.